Dci handling for enhanced cross-carrier scheduling

ABSTRACT

There is presented a method implemented in a network node that is operating as a secondary cell and that is configured to communicate with a wireless device and a primary cell for the wireless device. The method includes scheduling a physical shared channel the primary cell for the wireless device using a physical downlink control channel, PDCCH, on the primary cell and a physical downlink control channel, PDCCH, on the secondary cell. There is also presented a network node, a method for a wireless device and a wireless device.

FIELD

The present disclosure relates to wireless communications, and inparticular, to cross-carrier scheduling with downlink controlinformation (DCI) handling.

INTRODUCTION

Carrier Aggregation

Carrier Aggregation (CA) is generally used in 3rd Generation PartnershipProject (3GPP) New Radio (NR, also referred to as 5th Generation (5G))and Long Term Evolution (LTE, also referred to as 4th Generation (4G))systems to improve wireless device transmit/receive data rate ascompared to systems which do not use CA. With CA, the wireless devicetypically operates initially on a single serving cell referred to as aprimary cell (Pcell). The Pcell is operated on a component carrier in afrequency band. The wireless device is then configured by thenetwork/network node with one or more secondary serving cells(SCell(s)). Each SCell can correspond to a component carrier (CC) in thesame frequency band (intra-band CA) or a different frequency band(inter-band CA) from the frequency band of the CC corresponding to thePcell. For the wireless device to transmit/receive data on the SCell(s)(e.g., by receiving downlink (DL)-shared channel (SCH) information on aphysical downlink shared channel (PDSCH) or by transmittinguplink-shared channel (UL-SCH) information/data on a physical uplinkshared channel (PUSCH)), the SCell(s) may need to be activated by thenetwork/network node. The SCell(s) can also be deactivated and laterreactivated as needed via activation/deactivation signaling.

Cross-Carrier Scheduling

For NR carrier aggregation, cross-carrier scheduling (CCS) has beenconsidered using the following framework:

-   -   1. The wireless device has a primary serving cell and can be        configured with one or more secondary serving cells (SCells).    -   2. For a given SCell with SCell index X,    -   a. if the SCell is configured with a ‘scheduling cell’ with cell        index Y (i.e., cross-carrier scheduling)        -   i. SCell X is referred to as the ‘scheduled cell’.        -   ii. The wireless device monitors DL PDCCH on the scheduling            cell Y for assignments/grants scheduling PDSCH/PUSCH            corresponding to Sell X.        -   iii. PDSCH/PUSCH corresponding to SCell X cannot be            scheduled for the wireless device using a serving cell other            than scheduling cell Y.    -   b. Otherwise        -   i. SCell X is the scheduling cell for SCell X (i.e.,            same-carrier scheduling)        -   ii. The wireless device monitors DL PDCCH on SCell X for            assignments/grants scheduling PDSCH/PUSCH corresponding to            SCell X        -   iii. PDSCH/PUSCH corresponding to SCell X may not be able to            be scheduled for the wireless device using a serving cell            other than SCell X    -   3. An SCell may not be able to be configured as a scheduling        cell for the primary cell as the primary cell may always be its        own scheduling cell.

With current CA and cross-carrier scheduling framework, a SCell cannotbe used for scheduling physical shared data channels such as PDSCH/PUSCHon the PCell. Adding additional scheduling cells for the PCell willrequire ways to handle the increase in wireless device capability thatis needed for the increase in PDCCH monitoring and decoding.

SUMMARY

Some embodiments advantageously provide methods, systems, andapparatuses for cross-carrier scheduling with downlink controlinformation (DCI) handling.

In one embodiment there is provided a network node. The network nodeoperating a secondary cell and is configured to communicate with awireless device and a primary cell for the wireless device. The networknode includes a radio interface and processing circuitry configured toschedule a physical shared channel on the primary cell for the wirelessdevice using a physical downlink control channel, PDCCH, on the primarycell and a physical downlink control channel, PDCCH, on the secondarycell.

In one embodiment there is provided a method. The method is implementedin a network node that is operating as a secondary cell and that isconfigured to communicate with a wireless device and a primary cell forthe wireless device. The method includes scheduling a physical sharedchannel the primary cell for the wireless device using a physicaldownlink control channel, PDCCH, on the primary cell and a physicaldownlink control channel, PDCCH, on the secondary cell.

In one embodiment there is provided a wireless device. The wirelessdevice configured to communicate with a primary cell and a secondarycell. Further the wireless device includes a radio interface andprocessing circuitry configured to receive scheduling from the primarycell using a PDCCH and scheduling from the secondary cell using a PDCCH,the scheduling configured to schedule a physical shared channel on theprimary cell for the wireless device.

In one embodiment there is provided a method. The method implemented bya wireless device that is configured to communicate with a primary celland a secondary cell. The method includes receiving scheduling from theprimary cell using a PDCCH and receiving a scheduling from the secondarycell using a PDCCH, the scheduling configured to schedule a physicalshared channel on the primary cell for the wireless device.

Further embodiments include a network node, where the DCI size budgetfor the primary cell scheduled by the primary cell and secondary cell issame as the DCI size budget for the primary cell scheduled by a singlecell. Thus, the total DCI size budget for primary cell and the secondarycell does not increase compared to case where the PDSCH for the primarycell is scheduled by only the primary. Adding a secondary cell to thescheduling of the primary cell such that both the primary cell and thesecondary cell may schedule the PDSCH or PUSCH on the primary cell doesnot increase the DCI size budget.

In further embodiments the DCI size budget for the secondary cellscheduling a primary cell and secondary cell scheduling a secondary cellis same as the DCI size budget for the secondary cell scheduled bysingle cell.

In other embodiments the wherein the DCI format used for the primarycell and the DCI format used for the secondary cell is sized matched,e.g. the DCI for the primary cell and the DCI format used for thesecondary cell has the same size. This is achieved e.g. by padding byincluding a carrier indicator field in the DCI format used for theprimary cell.

A PCell can normally only be scheduled by the PCell. For a wirelessdevice there is normally an upper limit on the number of different DCIsizes that the wireless can monitor The embodiments enable an SCell tobe used for scheduling PDSCH/PUSCH on the PCell by restricting the DCI,for example restricting the number of different DCI sizes. Adding one ormore scheduling cells for the PCell, the SCell in this case couldotherwise necessitate an increase in the BDs/CCEs budget. An increase inthe BDs/CCEs budget would then require more wireless device processingand computational power and could also require increased wireless devicecomplexity.

In one or more embodiments, one or more of the following are provided:applying an aggregate budget over a set of scheduling cases (e.g., overall DCIs for the primary cell or overall DCIs monitored on SCell thatschedules primary cell) and/or applying restrictions on the monitoringof some DCIs for the primary cell in different scheduling cells. In someembodiments, a carrier indicator field is introduced for some DCIformats monitored on the primary cell even though the primary cell isnot the scheduling cell for any other SCell. In some embodiments, whenthe SCell is a DL-only SCell, one or more of the unused UL DCI formats(or size budget) available in the SCell are utilized for schedulingprimary cell uplink without the need for CIF in DCI formats.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic diagram of an example network architectureillustrating a communication system connected via an intermediatenetwork to a host computer according to the principles in the presentdisclosure;

FIG. 2 is a block diagram of a host computer communicating via a networknode with a wireless device over an at least partially wirelessconnection according to some embodiments of the present disclosure;

FIG. 3 is a flowchart illustrating example methods implemented in acommunication system including a host computer, a network node and awireless device for executing a client application at a wireless deviceaccording to some embodiments of the present disclosure;

FIG. 4 is a flowchart illustrating example methods implemented in acommunication system including a host computer, a network node and awireless device for receiving user data at a wireless device accordingto some embodiments of the present disclosure;

FIG. 5 is a flowchart illustrating example methods implemented in acommunication system including a host computer, a network node and awireless device for receiving user data from the wireless device at ahost computer according to some embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating example methods implemented in acommunication system including a host computer, a network node and awireless device for receiving user data at a host computer according tosome embodiments of the present disclosure;

FIG. 7 is a flowchart of an example process in a network node accordingto some embodiments of the present disclosure;

FIG. 8 is a flowchart of an example process in a wireless deviceaccording to some embodiments of the present disclosure;

FIG. 9 is a diagram of a DSS scenario according to some embodiments ofthe present disclosure;

FIGS. 10 a-c are diagrams of different scenarios of a scheduling cellaccording to some embodiments of the disclosure;

FIG. 11 is a diagram of an example of DCI format monitoring according tosome embodiments of the disclosure;

FIG. 12 is a diagram of another example of DCI format monitoringaccording to some embodiments of the disclosure;

FIG. 13 is a diagram of an example of DCI budgeting according to someembodiments of the disclosure; and

FIG. 14 is a diagram of an example of DCI scheduling according to someembodiments of the disclosure.

DETAILED DESCRIPTION

In one or more embodiments, described herein advantageouslyenable/configure a SCell to be used for scheduling PDSCH/PUSCH on theprimary cell with a DCI size budget handling with reduced complexity aswell as, in some cases, improved performance where overhead due tocarrier indicator field can be avoided.

Before describing in detail example embodiments, it is noted that theembodiments reside primarily in combinations of apparatus components andprocessing steps related to cross-carrier scheduling with DCI handlingAccordingly, components have been represented where appropriate byconventional symbols in the drawings, showing only those specificdetails that are pertinent to understanding the embodiments so as not toobscure the disclosure with details that will be readily apparent tothose of ordinary skill in the art having the benefit of the descriptionherein. Like numbers refer to like elements throughout the description.

As used herein, relational terms, such as “first” and “second,” “top”and “bottom,” and the like, may be used solely to distinguish one entityor element from another entity or element without necessarily requiringor implying any physical or logical relationship or order between suchentities or elements. The terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting of the concepts described herein. As used herein, the singularforms “a”, “an” and “the” are intended to include the plural forms aswell, unless the context clearly indicates otherwise. It will be furtherunderstood that the terms “comprises,” “comprising,” “includes” and/or“including” when used herein, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof.

In embodiments described herein, the joining term, “in communicationwith” and the like, may be used to indicate electrical or datacommunication, which may be accomplished by physical contact, induction,electromagnetic radiation, radio signaling, infrared signaling oroptical signaling, for example. One having ordinary skill in the artwill appreciate that multiple components may interoperate andmodifications and variations are possible of achieving the electricaland data communication.

In some embodiments described herein, the term “coupled,” “connected,”and the like, may be used herein to indicate a connection, although notnecessarily directly, and may include wired and/or wireless connections.

The term “network node” used herein can be any kind of network nodecomprised in a radio network which may further comprise any of basestation (BS), radio base station, base transceiver station (BTS), basestation controller (BSC), radio network controller (RNC), g Node B(gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio(MSR) radio node such as MSR BS, multi-cell/multicast coordinationentity (MCE), integrated access and backhaul (IAB) node, relay node,donor node controlling relay, radio access point (AP), transmissionpoints, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head(RRH), a core network node (e.g., mobile management entity (MME),self-organizing network (SON) node, a coordinating node, positioningnode, MDT node, etc.), an external node (e.g., 3rd party node, a nodeexternal to the current network), nodes in distributed antenna system(DAS), a spectrum access system (SAS) node, an element management system(EMS), etc. The network node may also comprise test equipment. The term“radio node” used herein may be used to also denote a wireless device(WD) such as a wireless device (WD) or a radio network node.

In some embodiments, the non-limiting terms wireless device (WD) or auser equipment (UE) are used interchangeably. The WD herein can be anytype of wireless device capable of communicating with a network node oranother WD over radio signals, such as wireless device (WD). The WD mayalso be a radio communication device, target device, device to device(D2D) WD, machine type WD or WD capable of machine to machinecommunication (M2M), low-cost and/or low-complexity WD, a sensorequipped with WD, Tablet, mobile terminals, smart phone, laptop embeddedequipped (LEE), laptop mounted equipment (LME), USB dongles, CustomerPremises Equipment (CPE), an Internet of Things (IoT) device, or aNarrowband IoT (NB-IOT) device etc.

Also, in some embodiments the generic term “radio network node” is used.It can be any kind of a radio network node which may comprise any ofbase station, radio base station, base transceiver station, base stationcontroller, network controller, RNC, evolved Node B (eNB), Node B, gNB,Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node,access point, radio access point, Remote Radio Unit (RRU) Remote RadioHead (RRH).

Note that although terminology from one particular wireless system, suchas, for example, 3GPP LTE and/or New Radio (NR), may be used in thisdisclosure, this should not be seen as limiting the scope of thedisclosure to only the aforementioned system. Other wireless systems,including without limitation Wide Band Code Division Multiple Access(WCDMA), Worldwide Interoperability for Microwave Access (WiMax), UltraMobile Broadband (UMB) and Global System for Mobile Communications(GSM), may also benefit from exploiting the ideas covered within thisdisclosure.

Note further, that functions described herein as being performed by awireless device or a network node may be distributed over a plurality ofwireless devices and/or network nodes. In other words, it iscontemplated that the functions of the network node and wireless devicedescribed herein are not limited to performance by a single physicaldevice and, in fact, can be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

Embodiments provide cross-carrier scheduling with DCI handling.Referring now to the drawing figures, in which like elements arereferred to by like reference numerals, there is shown in FIG. 1 aschematic diagram of a communication system 10, according to anembodiment, such as a 3GPP-type cellular network that may supportstandards such as LTE and/or NR (5G), which comprises an access network12, such as a radio access network, and a core network 14. The accessnetwork 12 comprises a plurality of network nodes 16 a, 16 b, 16 c(referred to collectively as network nodes 16), such as NBs, eNBs, gNBsor other types of wireless access points, each defining a correspondingcoverage area 18 a, 18 b, 18 c (referred to collectively as coverageareas 18). Each network node 16 a, 16 b, 16 c is connectable to the corenetwork 14 over a wired or wireless connection 20. A first wirelessdevice (WD) 22 a located in coverage area 18 a is configured towirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22 b in coverage area 18 b is wirelessly connectable tothe corresponding network node 16 b. While a plurality of WDs 22 a, 22 b(collectively referred to as wireless devices 22) are illustrated inthis example, the disclosed embodiments are equally applicable to asituation where a sole WD is in the coverage area or where a sole WD isconnecting to the corresponding network node 16. Note that although onlytwo WDs 22 and three network nodes 16 are shown for convenience, thecommunication system may include many more WDs 22 and network nodes 16.

Also, it is contemplated that a WD 22 can be in simultaneouscommunication and/or configured to separately communicate with more thanone network node 16 and more than one type of network node 16. Forexample, a WD 22 can have dual connectivity with a network node 16 thatsupports LTE and the same or a different network node 16 that supportsNR. As an example, WD 22 can be in communication with an eNB forLTE/E-UTRAN and a gNB for NR/NG-RAN.

The communication system 10 may itself be connected to a host computer24, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. The host computer 24 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider. Theconnections 26, 28 between the communication system 10 and the hostcomputer 24 may extend directly from the core network 14 to the hostcomputer 24 or may extend via an optional intermediate network 30. Theintermediate network 30 may be one of, or a combination of more than oneof, a public, private or hosted network. The intermediate network 30, ifany, may be a backbone network or the Internet. In some embodiments, theintermediate network 30 may comprise two or more sub-networks (notshown).

The communication system of FIG. 1 as a whole enables connectivitybetween one of the connected WDs 22 a, 22 b and the host computer 24.The connectivity may be described as an over-the-top (OTT) connection.The host computer 24 and the connected WDs 22 a, 22 b are configured tocommunicate data and/or signaling via the OTT connection, using theaccess network 12, the core network 14, any intermediate network 30 andpossible further infrastructure (not shown) as intermediaries. The OTTconnection may be transparent in the sense that at least some of theparticipating communication devices through which the OTT connectionpasses are unaware of routing of uplink and downlink communications. Forexample, a network node 16 may not or need not be informed about thepast routing of an incoming downlink communication with data originatingfrom a host computer 24 to be forwarded (e.g., handed over) to aconnected WD 22 a. Similarly, the network node 16 need not be aware ofthe future routing of an outgoing uplink communication originating fromthe WD 22 a towards the host computer 24.

A network node 16 is configured to include an enhancement unit 32 whichis configured to perform one or more network node 16 functions asdescribed herein such as with respect to cross-carrier scheduling withDCI handling. A wireless device 22 is configured to include an operationunit 34 which is configured to perform one or more wireless device 22functions as described herein such as with respect to cross-carrierscheduling with DCI handling.

Example implementations, in accordance with an embodiment, of the WD 22,network node 16 and host computer 24 discussed in the precedingparagraphs will now be described with reference to FIG. 2 . In acommunication system 10, a host computer 24 comprises hardware (HW) 38including a communication interface 40 configured to set up and maintaina wired or wireless connection with an interface of a differentcommunication device of the communication system 10. The host computer24 further comprises processing circuitry 42, which may have storageand/or processing capabilities. The processing circuitry 42 may includea processor 44 and memory 46. In particular, in addition to or insteadof a processor, such as a central processing unit, and memory, theprocessing circuitry 42 may comprise integrated circuitry for processingand/or control, e.g., one or more processors and/or processor coresand/or FPGAs (Field Programmable Gate Array) and/or ASICs (ApplicationSpecific Integrated Circuitry) adapted to execute instructions. Theprocessor 44 may be configured to access (e.g., write to and/or readfrom) memory 46, which may comprise any kind of volatile and/ornonvolatile memory, e.g., cache and/or buffer memory and/or RAM (RandomAccess Memory) and/or ROM (Read-Only Memory) and/or optical memoryand/or EPROM (Erasable Programmable Read-Only Memory).

Processing circuitry 42 may be configured to control any of the methodsand/or processes described herein and/or to cause such methods, and/orprocesses to be performed, e.g., by host computer 24. Processor 44corresponds to one or more processors 44 for performing host computer 24functions described herein. The host computer 24 includes memory 46 thatis configured to store data, programmatic software code and/or otherinformation described herein. In some embodiments, the software 48and/or the host application 50 may include instructions that, whenexecuted by the processor 44 and/or processing circuitry 42, causes theprocessor 44 and/or processing circuitry 42 to perform the processesdescribed herein with respect to host computer 24. The instructions maybe software associated with the host computer 24.

The software 48 may be executable by the processing circuitry 42. Thesoftware 48 includes a host application 50. The host application 50 maybe operable to provide a service to a remote user, such as a WD 22connecting via an OTT connection 52 terminating at the WD 22 and thehost computer 24. In providing the service to the remote user, the hostapplication 50 may provide user data which is transmitted using the OTTconnection 52. The “user data” may be data and information describedherein as implementing the described functionality. In one embodiment,the host computer 24 may be configured for providing control andfunctionality to a service provider and may be operated by the serviceprovider or on behalf of the service provider. The processing circuitry42 of the host computer 24 may enable the host computer 24 to observe,monitor, control, transmit to and/or receive from the network node 16and or the wireless device 22. The processing circuitry 42 of the hostcomputer 24 may include an information unit 54 configured to enable theservice provider to process, store, transmit, receive, forward, relay,determine, configure, reconfigure, etc., information related tocross-carrier scheduling with DCI handling that is described herein.

The communication system 10 further includes a network node 16 providedin a communication system 10 and including hardware 58 enabling it tocommunicate with the host computer 24 and with the WD 22. The hardware58 may include a communication interface 60 for setting up andmaintaining a wired or wireless connection with an interface of adifferent communication device of the communication system 10, as wellas a radio interface 62 for setting up and maintaining at least awireless connection 64 with a WD 22 located in a coverage area 18 servedby the network node 16. The radio interface 62 may be formed as or mayinclude, for example, one or more RF transmitters, one or more RFreceivers, and/or one or more RF transceivers. The communicationinterface 60 may be configured to facilitate a connection 66 to the hostcomputer 24. The connection 66 may be direct or it may pass through acore network 14 of the communication system 10 and/or through one ormore intermediate networks 30 outside the communication system 10.

In the embodiment shown, the hardware 58 of the network node 16 furtherincludes processing circuitry 68. The processing circuitry 68 mayinclude a processor 70 and a memory 72. In particular, in addition to orinstead of a processor, such as a central processing unit, and memory,the processing circuitry 68 may comprise integrated circuitry forprocessing and/or control, e.g., one or more processors and/or processorcores and/or FPGAs (Field Programmable Gate Array) and/or ASICs(Application Specific Integrated Circuitry) adapted to executeinstructions. The processor 70 may be configured to access (e.g., writeto and/or read from) the memory 72, which may comprise any kind ofvolatile and/or nonvolatile memory, e.g., cache and/or buffer memoryand/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/oroptical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the network node 16 further has software 74 stored internally in,for example, memory 72, or stored in external memory (e.g., database,storage array, network storage device, etc.) accessible by the networknode 16 via an external connection. The software 74 may be executable bythe processing circuitry 68. The processing circuitry 68 may beconfigured to control any of the methods and/or processes describedherein and/or to cause such methods, and/or processes to be performed,e.g., by network node 16. Processor 70 corresponds to one or moreprocessors 70 for performing network node 16 functions described herein.The memory 72 is configured to store data, programmatic software codeand/or other information described herein. In some embodiments, thesoftware 74 may include instructions that, when executed by theprocessor 70 and/or processing circuitry 68, causes the processor 70and/or processing circuitry 68 to perform the processes described hereinwith respect to network node 16. For example, processing circuitry 68 ofthe network node 16 may include enhancement unit 32 configured toperform one or more network node 16 functions as described herein suchas with respect to cross-carrier scheduling with DCI handling.

The communication system 10 further includes the WD 22 already referredto. The WD 22 may have hardware 80 that may include a radio interface 82configured to set up and maintain a wireless connection 64 with anetwork node 16 serving a coverage area 18 in which the WD 22 iscurrently located. The radio interface 82 may be formed as or mayinclude, for example, one or more RF transmitters, one or more RFreceivers, and/or one or more RF transceivers.

The hardware 80 of the WD 22 further includes processing circuitry 84.The processing circuitry 84 may include a processor 86 and memory 88. Inparticular, in addition to or instead of a processor, such as a centralprocessing unit, and memory, the processing circuitry 84 may compriseintegrated circuitry for processing and/or control, e.g., one or moreprocessors and/or processor cores and/or FPGAs (Field Programmable GateArray) and/or ASICs (Application Specific Integrated Circuitry) adaptedto execute instructions. The processor 86 may be configured to access(e.g., write to and/or read from) memory 88, which may comprise any kindof volatile and/or nonvolatile memory, e.g., cache and/or buffer memoryand/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/oroptical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the WD 22 may further comprise software 90, which is stored in,for example, memory 88 at the WD 22, or stored in external memory (e.g.,database, storage array, network storage device, etc.) accessible by theWD 22. The software 90 may be executable by the processing circuitry 84.The software 90 may include a client application 92. The clientapplication 92 may be operable to provide a service to a human ornon-human user via the WD 22, with the support of the host computer 24.In the host computer 24, an executing host application 50 maycommunicate with the executing client application 92 via the OTTconnection 52 terminating at the WD 22 and the host computer 24. Inproviding the service to the user, the client application 92 may receiverequest data from the host application 50 and provide user data inresponse to the request data. The OTT connection 52 may transfer boththe request data and the user data. The client application 92 mayinteract with the user to generate the user data that it provides.

The processing circuitry 84 may be configured to control any of themethods and/or processes described herein and/or to cause such methods,and/or processes to be performed, e.g., by WD 22. The processor 86corresponds to one or more processors 86 for performing WD 22 functionsdescribed herein. The WD 22 includes memory 88 that is configured tostore data, programmatic software code and/or other informationdescribed herein. In some embodiments, the software 90 and/or the clientapplication 92 may include instructions that, when executed by theprocessor 86 and/or processing circuitry 84, causes the processor 86and/or processing circuitry 84 to perform the processes described hereinwith respect to WD 22. For example, the processing circuitry 84 of thewireless device 22 may include an operation unit 34 configured toperform one or more wireless device 22 functions as described hereinsuch as with respect to cross-carrier scheduling with DCI handling.

Dual Connectivity

Dual Connectivity (DC) is generally used in NR (5G) and LTE systems tohelp improve wireless device transmit and receive data rates. With DC,the wireless device typically operates with a master cell group (MCG)and a secondary cell group (SCG). Each cell group can have one or moreserving cells. The MCG cell, operating on the primary frequency, inwhich the wireless device either performs the initial connectionestablishment procedure or initiates the connection re-establishmentprocedure, is referred to as the primary cell or PCell. The SCG cell inwhich the wireless device performs random access when performing theReconfiguration with Sync procedure is referred to as the primary SCGcell or PSCell.

In some cases, the term “primary cell” or “primary serving cell” canrefer to PCell for a wireless device not configured with DC, and/or canrefer to PCell of MCG or PSCell of SCG for a wireless device configuredwith DC.

PDCCH Monitoring

In third generation partnership project (3GPP) NR standards, downlinkcontrol information (DCI) is received over the physical (i.e., physicallayer) downlink control channel (PDCCH). The PDCCH may carry DCI inmessages with different formats. DCI format 0_0, 0_1, and 0_2, forexample, are DCI messages used to convey uplink grants to the wirelessdevice for transmission of the physical (i.e., physical layer) datachannel in the uplink (PUSCH) and DCI format 1_0, 1_1, and 1_2, forexample, are used to convey downlink grants for transmission of thephysical layer data channel in the downlink (PDSCH). Other DCI formats(e.g., DCI 2_0, 2_1, 2_2 and 2_3) are used for other purposes such astransmission of slot format information, reserved resource, transmitpower control information, etc.

A PDCCH candidate is searched within a common or wirelessdevice-specific search space which is mapped to a set of time andfrequency resources referred to as a control resource set (CORESET). Thesearch spaces within which PDCCH candidates may be required to bemonitored and are configured/indicated to the wireless device via radioresource control (RRC) signaling. A monitoring periodicity is alsoconfigured for different PDCCH candidates. In any particular slot, thewireless device may be configured to monitor multiple PDCCH candidatesin multiple search spaces which may be mapped to one or more CORESETs.PDCCH candidates may need to be monitored multiple times in a slot, onceevery slot or once in multiple of slots.

The smallest unit used for defining CORESETs is a Resource Element Group(REG) which is defined as spanning 1 PRB×1 OFDM symbol in frequency andtime. Each REG contains demodulation reference signals (DM-RS) to aid inthe estimation of the radio channel over which that REG was transmitted.When transmitting the PDCCH, a precoder could be used to apply weightsat the transmit antennas based on some knowledge of the radio channelprior to transmission. It is possible to improve channel estimationperformance at the wireless device by estimating the channel overmultiple REGs that are proximate in time and frequency if the precoderused at the transmitter for the REGs is not different. To assist thewireless device with channel estimation, the multiple REGs can begrouped together to form a REG bundle and the REG bundle size for aCORESET is indicated to the wireless device. The wireless device mayassume that any precoder used for the transmission of the PDCCH is thesame for all the REGs in the REG bundle. A REG bundle may consist of 2,3 or 6 REGs.

A control channel element (CCE) may consist of 6 REGs. The REGs within aCCE may either be contiguous or distributed in frequency. When the REGsare distributed in frequency, the CORESET is said to be using aninterleaved mapping of REGs to a CCE and if the REGs are not distributedin frequency, a non-interleaved mapping is said to be used.

A PDCCH candidate may span 1, 2, 4, 8 or 16 CCEs. The number ofaggregated CCEs used is referred to as the aggregation level for thePDCCH candidate.

A hashing function is used to determine the CCEs corresponding to PDCCHcandidates that a wireless device may have to monitor within a searchspace set. The hashing can be done/determined/performed differently fordifferent wireless devices so that the CCEs used by the wireless devicesare randomized and the probability of collisions between multiplewireless devices for which PDCCH messages are included in a CORESET isreduced.

Blind decoding (BD) of potential PDCCH transmissions is attempted by thewireless device in each of the configured PDCCH candidates within aslot. The complexity incurred, at the wireless device, to perform theblind decoding may depend on a number of blind decoding attempts and thenumber of CCEs which need to be processed.

In order to manage complexity, limits on the total number of CCEs and/ortotal number of blind decodes to be processed by the wireless devicehave been discussed and a possible technique for BD/CCE partitioningbased on wireless device capability has been adopted for NR operationwith multiple component carriers.

Blind Decoding and CCE Handling for Carrier Aggregation

In existing NR standards, a scheduled cell has only one scheduling cellwhere the primary cell may always perform the scheduling for the primarycell. A scheduling cell carries DCI for scheduling itself and can carryDCI for scheduling other cells. When a wireless device is configuredwith cross-carrier scheduling, the PDCCH carrying the DCI format forscheduling the PDSCH/PUSCH on the scheduled cell is sent on a schedulingcell. In such a case, a carrier indicator field is included in the DCIformats (e.g., non-fallback DCI formats such as 0-1/1-1 for schedulingPUSCH/PDSCH) on the scheduling cell. Higher layer configurationindicates the linkages between the scheduled/scheduling cells, the CIFvalue to monitor, and the corresponding search space configuration formonitoring DCI formats of a scheduled cell on the scheduling cell, etc.

A wireless device can be configured with up to three CORESETs and up toten search spaces for each DL bandwidth part (BWP) in a scheduling cell.The network node can configure the search spaces that a wireless devicemonitors according to some constraints or limits on maximum number ofblind decodes and control channel elements.

DCI Size Budget

In NR 3GPP Release 15 (Rel-15), for each BWP of a scheduled cell, thereis an upper limit on the number of different DCI sizes that the wirelessdevice can monitor. The wireless device may not be expected to handle aconfiguration that results in 1) the total number of different DCI sizesconfigured to monitor is more than 4 for the cell or 2) the total numberof different DCI sizes with C-RNTI configured to monitor is more than 3for the cell.

A size-matching procedure is defined for some DCIs (e.g.,0-0/1-0/1-1/0-1 in some search spaces) which can be used to ensure theDCI size budget is not exceeded. For some DCIs such as 2-0, 2-6, the DCIsize is explicitly configured by higher layers, but the network node mayconfigure such that wireless budget is not exceeded.

Default QCL Assumption in Cross-Carrier Scheduling

In case of cross-carrier scheduling, the PDCCH to PDSCH gap is less thana certain threshold, the default TCI state to assume for that PDSCH canbe given by the TCI state with lowest index of the TCI states configuredfor the PDSCH.

In some embodiments, the inner workings of the network node 16, WD 22,and host computer 24 may be as shown in FIG. 2 and independently, thesurrounding network topology may be that of FIG. 1 .

In FIG. 2 , the OTT connection 52 has been drawn abstractly toillustrate the communication between the host computer 24 and thewireless device 22 via the network node 16, without explicit referenceto any intermediary devices and the precise routing of messages viathese devices. Network infrastructure may determine the routing, whichit may be configured to hide from the WD 22 or from the service provideroperating the host computer 24, or both. While the OTT connection 52 isactive, the network infrastructure may further take decisions by whichit dynamically changes the routing (e.g., on the basis of load balancingconsideration or reconfiguration of the network).

The wireless connection 64 between the WD 22 and the network node 16 isin accordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to the WD 22 using the OTTconnection 52, in which the wireless connection 64 may form the lastsegment. More precisely, the teachings of some of these embodiments mayimprove the data rate, latency, and/or power consumption and therebyprovide benefits such as reduced user waiting time, relaxed restrictionon file size, better responsiveness, extended battery lifetime, etc.

In some embodiments, a measurement procedure may be provided for thepurpose of monitoring data rate, latency and other factors on which theone or more embodiments improve. There may further be an optionalnetwork functionality for reconfiguring the OTT connection 52 betweenthe host computer 24 and WD 22, in response to variations in themeasurement results. The measurement procedure and/or the networkfunctionality for reconfiguring the OTT connection 52 may be implementedin the software 48 of the host computer 24 or in the software 90 of theWD 22, or both. In embodiments, sensors (not shown) may be deployed inor in association with communication devices through which the OTTconnection 52 passes; the sensors may participate in the measurementprocedure by supplying values of the monitored quantities exemplifiedabove, or supplying values of other physical quantities from whichsoftware 48, 90 may compute or estimate the monitored quantities. Thereconfiguring of the OTT connection 52 may include message format,retransmission settings, preferred routing etc.; the reconfiguring neednot affect the network node 16, and it may be unknown or imperceptibleto the network node 16. Some such procedures and functionalities may beknown and practiced in the art. In certain embodiments, measurements mayinvolve proprietary WD signaling facilitating the host computer's 24measurements of throughput, propagation times, latency and the like. Insome embodiments, the measurements may be implemented in that thesoftware 48, 90 causes messages to be transmitted, in particular emptyor ‘dummy’ messages, using the OTT connection 52 while it monitorspropagation times, errors etc.

Thus, in some embodiments, the host computer 24 includes processingcircuitry 42 configured to provide user data and a communicationinterface 40 that is configured to forward the user data to a cellularnetwork for transmission to the WD 22. In some embodiments, the cellularnetwork also includes the network node 16 with a radio interface 62. Insome embodiments, the network node 16 is configured to, and/or thenetwork node's 16 processing circuitry 68 is configured to perform thefunctions and/or methods described herein forpreparing/initiating/maintaining/supporting/ending a transmission to theWD 22, and/or preparing/terminating/maintaining/supporting/ending inreceipt of a transmission from the WD 22.

In some embodiments, the host computer 24 includes processing circuitry42 and a communication interface 40 that is configured to acommunication interface 40 configured to receive user data originatingfrom a transmission from a WD 22 to a network node 16. In someembodiments, the WD 22 is configured to, and/or comprises a radiointerface 82 and/or processing circuitry 84 configured to perform thefunctions and/or methods described herein forpreparing/initiating/maintaining/supporting/ending a transmission to thenetwork node 16, and/orpreparing/terminating/maintaining/supporting/ending in receipt of atransmission from the network node 16.

Although FIGS. 1 and 2 show various “units” such as enhancement unit 32,and operation unit 34 as being within a respective processor, it iscontemplated that these units may be implemented such that a portion ofthe unit is stored in a corresponding memory within the processingcircuitry. In other words, the units may be implemented in hardware orin a combination of hardware and software within the processingcircuitry.

FIG. 3 is a flowchart illustrating an example method implemented in acommunication system, such as, for example, the communication system ofFIGS. 1 and 2 , in accordance with one embodiment. The communicationsystem may include a host computer 24, a network node 16 and a WD 22,which may be those described with reference to FIG. 2 . In a first stepof the method, the host computer 24 provides user data (Block S100). Inan optional substep of the first step, the host computer 24 provides theuser data by executing a host application, such as, for example, thehost application 50 (Block S102). In a second step, the host computer 24initiates a transmission carrying the user data to the WD 22 (BlockS104). In an optional third step, the network node 16 transmits to theWD 22 the user data which was carried in the transmission that the hostcomputer 24 initiated, in accordance with the teachings of theembodiments described throughout this disclosure (Block S106). In anoptional fourth step, the WD 22 executes a client application, such as,for example, the client application 92, associated with the hostapplication 50 executed by the host computer 24 (Block S108).

FIG. 4 is a flowchart illustrating an example method implemented in acommunication system, such as, for example, the communication system ofFIG. 1 , in accordance with one embodiment. The communication system mayinclude a host computer 24, a network node 16 and a WD 22, which may bethose described with reference to FIGS. 1 and 2 . In a first step of themethod, the host computer 24 provides user data (Block S110). In anoptional substep (not shown) the host computer 24 provides the user databy executing a host application, such as, for example, the hostapplication 50. In a second step, the host computer 24 initiates atransmission carrying the user data to the WD 22 (Block S112). Thetransmission may pass via the network node 16, in accordance with theteachings of the embodiments described throughout this disclosure. In anoptional third step, the WD 22 receives the user data carried in thetransmission (Block S114).

FIG. 5 is a flowchart illustrating an example method implemented in acommunication system, such as, for example, the communication system ofFIG. 1 , in accordance with one embodiment. The communication system mayinclude a host computer 24, a network node 16 and a WD 22, which may bethose described with reference to FIGS. 1 and 2 . In an optional firststep of the method, the WD 22 receives input data provided by the hostcomputer 24 (Block S116). In an optional substep of the first step, theWD 22 executes the client application 92, which provides the user datain reaction to the received input data provided by the host computer 24(Block S118). Additionally or alternatively, in an optional second step,the WD 22 provides user data (Block S120). In an optional substep of thesecond step, the WD provides the user data by executing a clientapplication, such as, for example, client application 92 (Block S122).In providing the user data, the executed client application 92 mayfurther consider user input received from the user. Regardless of thespecific manner in which the user data was provided, the WD 22 mayinitiate, in an optional third substep, transmission of the user data tothe host computer 24 (Block S124). In a fourth step of the method, thehost computer 24 receives the user data transmitted from the WD 22, inaccordance with the teachings of the embodiments described throughoutthis disclosure (Block S126).

FIG. 6 is a flowchart illustrating an example method implemented in acommunication system, such as, for example, the communication system ofFIG. 1 , in accordance with one embodiment. The communication system mayinclude a host computer 24, a network node 16 and a WD 22, which may bethose described with reference to FIGS. 1 and 2 . In an optional firststep of the method, in accordance with the teachings of the embodimentsdescribed throughout this disclosure, the network node 16 receives userdata from the WD 22 (Block S128). In an optional second step, thenetwork node 16 initiates transmission of the received user data to thehost computer 24 (Block S130). In a third step, the host computer 24receives the user data carried in the transmission initiated by thenetwork node 16 (Block S132).

FIG. 7 is a flowchart of an example process in a network node 16according to some embodiments of the present disclosure. One or moreBlocks and/or functions performed by network node 16 may be performed byone or more elements of network node 16 such as by enhancement unit 32in processing circuitry 68, processor 70, radio interface 62, etc. Inone or more embodiments, network node 16 such as via one or more ofprocessing circuitry 68, processor 70, enhancement unit 32,communication interface 60 and radio interface 62 is configured toschedule (Block S134) a physical shared channel such as a PDSCH or aPUSCH on the primary cell for the wireless 22 device using a PDCCH onthe primary cell and a PDCCH on the secondary cell, as described herein.In one or more embodiments, network node 16 such as via one or more ofprocessing circuitry 68, processor 70, enhancement unit 32,communication interface 60 and radio interface 62 is configured tooptionally cause (Block S136) transmission of the scheduling, asdescribed herein.

According to one or more embodiments, the scheduling of at least one ofthe physical shared channel and physical control channel on the primarycell is performed by a physical downlink control channel, PDCCH, on thesecondary cell. According to one or more embodiments, a downlink controlinformation, DCI, budget for the wireless device for both the primarycell and secondary cell corresponds to a total number of DCIs sizes thatthe wireless device is provided is shared among the primary cell and isthe same as the DCI budget for one of the primary cell and secondarycell.

FIG. 8 is a flowchart of an example process in a wireless device 22according to some embodiments of the present disclosure. One or moreBlocks and/or functions performed by wireless device 22 may be performedby one or more elements of wireless device 22 such as by operation unit34 in processing circuitry 84, processor 86, radio interface 82, etc. Inone or more embodiments, wireless device such as via one or more ofprocessing circuitry 84, processor 86, operation unit 34 and radiointerface 82 is configured to receive (Block S138) receive schedulingfrom the primary cell using a PDCCH and receiving scheduling from thesecondary cell using a PDCCH, the scheduling is configured to schedule aphysical shared channel such as PDSCH or PUSCH on the primary cell forthe wireless device, as described herein. In one or more embodiments,wireless device such as via one or more of processing circuitry 84,processor 86, operation unit 34 and radio interface 82 is configured tooptimally operate (Block S140) according to the received scheduling, asdescribed herein.

According to one or more embodiments, the scheduling of at least one ofthe physical shared channel and physical control channel on the primarycell is received via a physical downlink control channel, PDCCH, on thesecondary cell. According to one or more embodiments, a downlink controlinformation, DCI, budget for the wireless device 22 for both the primarycell and secondary cell corresponds to a total number of DCIs sizes thatthe wireless device 22 is provided is shared among the primary cell andis the same as the DCI budget for one of the primary cell and secondarycell.

Having generally described arrangements for cross-carrier schedulingwith DCI handling, details for these arrangements, functions andprocesses are provided as follows, and which may be implemented by thenetwork node 16, wireless device 22 and/or host computer 24.

Embodiments Provide Cross-Carrier Scheduling with DCI Handling.

DSS Scenario and Enhanced CCS Framework

FIG. 9 is a diagram of an example DSS scenario. FIG. 9 illustrates slotsfor a NR PCell/PSCell (primary cell) provided by, for example, networknode 16, for a DL CA capable wireless device 22 operated on a carrierwhere the same carrier is also used for serving wireless devices of adifferent radio access technology (e.g., LTE (4G)) via dynamic spectrumsharing, and slots for another NR SCell configured for the same wirelessdevice.

As shown in FIG. 9 , when a NR primary cell is operated on the samecarrier on which legacy LTE wireless devices 22 are served, theopportunities for transmitting PDCCH may be significantly limited due tothe need to avoid overlap with LTE transmissions (e.g., LTE PDCCH, LTEPDSCH, LTE CRS).

For a wireless device 22 supporting DL CA, providing the ability to useSCell PDCCH to schedule primary cell PDSCH/PUSCH (e.g., as shown bydashed arrows in FIG. X1 ) helps in reducing the loading of primary cellPDCCH.

The example illustrated in FIG. 9 is for a CA scenario for a DL CAcapable wireless device 22 with NR primary cell on FDD carriers with 15kHz SCS and NR SCell on TDD carrier with 30 kHz SCS. This is just onescenarios, where the teachings described herein are equally applicableto other scenarios (e.g., SCell being operated on FDD band) with 15 kHzSCS are also possible.

Enhanced CCS Framework with Special SCell (sSCell)

To enable/configure support of SCell scheduling such as via one or moreof processing circuitry 68, processor 70, radio interface 62,enhancement unit 32, etc., PDSCH/PUSCH on primary cell, the existing NRCCS framework can be enhanced/configured/modified as follows:

-   -   1. In one or more embodiments, the network node 16 may RRC        configure a DL CA capable wireless device 22 with at least one        SCell such that PDCCH on that SCell can schedule PUSCH and/or        PDSCH on the primary cell. Such an SCell is referred to as,        e.g., a special SCell (sSCell).    -   2. When wireless device 22 is configured with sSCell:        -   a. PDCCH on primary cell may only schedule PDSCH/PUSCH            transmissions on the primary cell (no CCS may be allowed            from primary cell);        -   b. PDCCH on sSCell can schedule such as via one or more of            processing circuitry 68, processor 70, radio interface 62,            enhancement unit 32, etc., PDSCH/PUSCH on            -   i. the primary cell of the cell group (CG) of the                sSCell;            -   ii. the sSCell (i.e., sSCell cannot be a ‘scheduled                cell’ for another cell); and/or            -   iii. other SCells in the same CG of sSCell for which the                sSCell is configured as a scheduling cell;        -   c. the primary cell can be considered to have ‘two            scheduling cells’, i.e., the primary cell itself and the            sSCell. Other serving cells may only have one scheduling            cell.

Above conditions simplify sSCell operation without reducing flexibility.For example, the main motivation of sSCell is to reduce PDCCH load onprimary cell and supporting CCS from primary cell would only increasePDCCH load. So, such combination is not required when sSCell isconfigured.

Blind Decoding and CCE Handling for Enhanced Cross-Carrier Scheduling

The wireless device 22 typically uses such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., the primary cell for initial access, link maintenance,and overall as an anchor cell for maintaining a network connection. Thewireless device 22 such as via one or more of processing circuitry 84,processor 86, radio interface 82, operation unit 34, etc., may alwaysmonitor the primary cell and the primary cell may always be a schedulingcell and may always be activated.

Enhanced cross-carrier scheduling is where a SCell such as via one ormore of processing circuitry 68, processor 70, radio interface 62,enhancement unit 32, etc., can also schedule transmission/reception onthe primary cell which can reduce the loading on the PDCCH of theprimary cell. One feature of enhanced cross-carrier scheduling is thatthe primary cell has two scheduling cells—the primary cell, itself, andan SCell (i.e., sSCell) that can also schedule the primary cell. In thiscase, one or more of the BD/CCE limits may be identified as the:

-   -   Maximum number of BDs/CCEs supported on the primary cell;    -   Maximum number of BDs/CCEs supported on the secondary cell for        scheduling the primary cell;    -   Maximum number of BDs/CCEs supported on the secondary cell for        scheduling the secondary cell; and/or    -   Maximum number of BDs/CCEs supported for scheduling the other        secondary cells.

Based on one or more of the identified limits above, the network node16/network can configure PDCCH candidates appropriately for thedifferent search spaces on different serving cells.

Some examples are illustrated in FIGS. 10 a-c where arrows denote thescheduling cell, scheduled cell relationship, and where the origin ofthe dashed line illustrates the scheduling cell, and where a scheduledcell pair are grouped with another pair of (scheduling cell, scheduledcell) for the purpose of BD/CCE limit calculation.

In FIG. 10 a , the primary cell is considered as the referencescheduling cell, and the primary cell that schedules primary cellcommunications and the sSCell that schedules such as via one or more ofprocessing circuitry 68, processor 70, radio interface 62, enhancementunit 32, etc., primary cell communications may share the same BD/CCEbudget that is determined using the primary cell scheduling primary cellas reference.

In FIG. 10 b , the sSCell is considered the reference scheduling cell,and the sSCell 1 that schedules such as via one or more of processingcircuitry 68, processor 70, radio interface 62, enhancement unit 32,etc., the primary cell and the primary cell that schedules the primarycell share the same BD/CCE budget that is determined using the sSCellscheduling primary cell as the reference.

In FIG. 10 c , the primary cell is considered as the referencescheduling cell, and the sSCell that schedules such as via one or moreof processing circuitry 68, processor 70, radio interface 62,enhancement unit 32, etc., the sSCell and the sSCell such as via one ormore of processing circuitry 68, processor 70, radio interface 62,enhancement unit 32, etc., that schedules the primary cell share thesame BD/CCE budget that is determined using the sSCell scheduling sSCellas reference.

DCIs and Search Space Types that May be Allowed/not Allowed for TwoCells Scheduling Same Cell

NR supports common search spaces and wireless device 22-specific searchspaces. A common search space can be of type 0/0A/1/2/3. The wirelessdevice monitors the common search space for DCI format 0-0/1-0 withassociated RNTIs, and group common DCI such as DCI 2-x (e.g. 2-0, 2-1,etc.).

When wireless device 22 is configured with a primary cell and one ormore SCells, and wireless device 22 may be configured with an sSCellwhere, in the sSCell, wireless device 22 may be configured such as viaone or more of processing circuitry 84, processor 86, radio interface82, operation unit 34, etc., to monitor only USS for DCI scheduling theprimary cell. In the sSCell, wireless device 22 can be configured suchas via one or more of processing circuitry 84, processor 86, radiointerface 82, operation unit 34, etc., to monitor one or more of thefollowing DCI scheduling the primary cell:

-   -   only non-fallback DCI (0-1/1-1/0-2/1-2),    -   only UL DCI        -   one or both of non-fallback and fallback DCI

In one or more embodiments, the DCI can contain a carrier indicatorfield (CIF) to indicate the cell for which the DCI is intended. Thecarrier indicator field can be included in non-fallback DCI only,fallback DCI or both.

In one or more embodiments, the carrier indicator field (CIF) may beomitted if there are other means for wireless device 22 such as via oneor more of processing circuitry 84, processor 86, radio interface 82,operation unit 34, etc., to determine the cell for which a DCI isintended. For instance, omission of CIF may be performed when sSCell isa DL-only cell and wireless device 22 such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., can be configured to monitor UL DCI formats 0-1 and/or0-0 on the sSCell where those UL DCI formats are used for primary cellscheduling. In another example, omission of CIF may be performed byconfiguring wireless device 22 such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,to monitor different search spaces for DCI formats 0-1 and/or 0-0 on thesSCells where different search spaces are used for primary cellscheduling and for sScell scheduling.

In the primary cell, wireless device 22 such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., can be configured to monitor a common search space (CSS),and possibly a user equipment search space (USS) for scheduling theprimary cell.

Some aspects of the overall framework for enhanced CCS, including someaspects of DCI handling and limits BDs/CCEs, are beyond the scope of thedisclosure.

DCI Size Budget for Primary Cell Scheduled by Two Cells

The DCI size budget is typically applied per scheduled cell. However,when sSCell is configured, the DCI size budgets may be applied in one ormore manners with low implementation complexity.

In some embodiments, the DCI size budget for the primary cell scheduledby two cells is same as the DCI size budget for the primary cellscheduled by single cell. More specifically, wireless device 22 may notbe expected to handle a configuration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the primary cell for scheduling of the primary cell and        configured to monitor on the sSCell for scheduling of the        primary cell is no more than 4; and    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the primary cell for scheduling of the primary        cell and configured to monitor on the sSCell for scheduling of        the primary cell is no more than 3.

In some embodiments, the DCI size budget for the sScell scheduling theprimary cell and sScell scheduling the sScell (i.e., scheduling itself)is same as the DCI size budget for the sScell scheduled by single cell.More specifically, wireless device 22 is not expected to handle aconfiguration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the sSCell for scheduling of the primary cell and configured to        monitor on the sSCell for scheduling of the sScell is no more        than 4; and    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the sScell for scheduling of the primary cell and        configured to monitor on the sSCell for scheduling of the sSCell        is no more than 3.

A DCI size matching procedure may be applied and zero-padding may beintroduced to satisfy/meet the budgets.

Some additional embodiments for DCI handling are described below.

Moving Only One DCI Format to sSCell′ Section

In this case, wireless device 22, such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,is configured to monitor a non-fallback DCI format for the primary cellon one serving cell only, e.g., DCI format 1-1 (non-fallback DCI for DL)is configured to be monitored only on Pcell and DCI format 0-1 (ornon-fallback DCI for UL) is configured to be monitored only on thesSCell.

The DCI format that is configured to be monitored in the sSCell cancarry the carrier indicator field. The DCI format that is configured tobe monitored in the primary cell may not carry the carrier indicatorfield, as illustrated in FIG. 11 , where wireless device 22 such as viaone or more of processing circuitry 84, processor 86, radio interface82, operation unit 34, etc., monitors a total of 4 DCIs for the primarycell (3 DCIs on the primary cell and one DCI on the sSCell). If the DCIsize budget for DCIs scheduling the primary cell (including the 0-1/0-2containing CIF on the sSCell scheduling primary cell) is exceeded, thensize matching is triggered/implemented (including any zero-padding ofDCIs) until the DCI size budget is satisfied.

In certain embodiments, wireless device 22, such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., can monitor DL DCI scheduling primary cell only on theprimary cell. Wireless device 22, such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,can monitor UL non-fallback DCI scheduling primary cell only on thesSCell. Wireless device 22, such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,can monitor fallback DCI for uplink scheduling on the primary cell. Thecarrier indicator field is included in only the UL non-fallback DCIscheduling the primary cell.

In certain embodiments, wireless device 2,2 such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., can monitor only one of “DL non-fallback DCI schedulingprimary cell” or “UL non-fallback DCI scheduling primary cell” on thesSCell, the DCI containing a carrier indicator field. On the primarycell, wireless device 22, such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,can monitor the other non-fallback DCI and fallback DCIs schedulingprimary cell on the primary cell, wherein the DCIs on the primary celldo not include a carrier indicator field.

The DCI size budget for sSCell scheduling the sSCell (i.e., sSCellscheduling itself) may be counted/considered separately.

“Using the Same Size for a DCI Format for the Primary Cell when the DCIFormat is Monitored on Both Cells”

Wireless device 22, such as via one or more of processing circuitry 84,processor 86, radio interface 82, operation unit 34, etc., is configuredto monitor a non-fallback DCI format scheduling the primary cell on bothserving cells (primary cell and sSCell) where the DCI format includesthe carrier indicator field in both serving cells, or the correspondingDCI format's size on the primary cell that is size-matched to that DCIformat's size on the sSCell. On the sSCell, DCI size-matching may not beneeded between DCIs scheduling primary cell and DCIs scheduling othercells.

When DCI format 1-1 (or DL non-fallback DCI) and DCI format 0-1 (or ULnon-fallback DCI) are configured to be monitored such as via one or moreof processing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., on the primary cell for scheduling the primary cell andare configured to be monitored on the sSCell for scheduling the primarycell, both DCI formats can carry the carrier indicator field in bothcells. This scenario is illustrated in FIG. 12 where wireless device 22such as via one or more of processing circuitry 84, processor 86, radiointerface 82, operation unit 34, etc., monitors a total of 4 DCI sizesfor the primary cell (4 DCIs on primary cell and two DCIs on sSCell,satisfying the budget of three DCI sizes with C-RNTI (e.g., due tosize-matching that kicks in for DCIs scheduling primary cell and sincethe same size of non-fallback DCI 0-1/1-1 is used in the primary andsSCell). While the CIF is illustrated separately in FIG. 12 , the CIFmay be considered as a field within the DCI formats.

The DCI size budget for sSCell scheduling the sSCell (i.e., schedulingitself) may be counted separately.

“Separate DCI Size Budget Treating ‘sSCell Scheduling of Primary Cell’as an Extra Virtual Cell”

The sSCell scheduling primary cell may be considered an extra virtualcell with its own DCI budget. This can be borrowed, e.g., when wirelessdevice 22 is under-utilizing its carrier aggregation capability.

Thus, the DCI budget for the primary cell scheduling the primary cell,i.e., itself, is independent from the DCI budget for the sSCellscheduling primary cell. An example is illustrated in FIG. 13 where theDCI formats 1-1 (non-fallback DCI for DL) and DCI format 0-1 (ornon-fallback DCI for UL) are configured to be monitored on sSCell andmay carry the carrier indicator field in both cells. Further, asillustrated in FIG. 13 , wireless device 22 such as via one or more ofprocessing circuitry 84, processor 86, radio interface 82, operationunit 34, etc., monitors a total 6 DCI sizes for the primary cell (4 DCIson primary cell and two DCIs on sSCell). For illustration, the CIF isshown separately but it is considered as a field within the DCI formats.The portions with hatchings indicate the enhanced elements that helpmake sSCell scheduling of the primary cell possible.

More specifically, wireless device 22 is not expected to handle aconfiguration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the primary cell for scheduling of the primary cell and        configured to monitor on the sSCell for scheduling of the        primary cell is no more than 8; and    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the primary cell for scheduling of the primary        cell and configured to monitor on the sSCell for scheduling of        the primary cell is no more than 6.

“Borrowing DCI Size from the sSCell Budget or Applying an AggregateBudget Over Primary Cell and sSCell”

In this case, the DCI size budget (4 total sizes and 3 sizes withC-RNTI) is maintained on the primary cell, but on the sSCell the DCIsizes for scheduling sSCell and for scheduling primary cell are countedwithin the same budget. In some cases, the DCI size budget is reduced onthe primary cell (3 total sizes and 2 sizes with C-RNTI) when sSCell isconfigured.

More specifically, wireless device 22 is not expected to handle aconfiguration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the sSCell for scheduling of the primary cell and configured to        monitor on the sSCell for scheduling of the sSCell is no more        than 4;    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the sScell for scheduling of the primary cell and        configured to monitor on the sSCell for scheduling of the sSCell        is no more than 3.

In addition, in some cases, wireless device 22 is not expected to handlea configuration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the primary cell for scheduling of the primary cell is no more        than 4;    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the primary cell for scheduling of the primary        cell is no more than 3.

In some other case, a larger DCI size budget is maintained togetheracross the primary cell and sSCell.

More specifically, wireless device 22 is not expected to handle aconfiguration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor on        the sSCell for scheduling of the primary cell and configured to        monitor on the sSCell for scheduling of the sSCell and        configured to monitor on the primary cell for scheduling of        primary cell is no more than 4+4=8;    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the sScell for scheduling of the primary cell and        configured to monitor on the sSCell for scheduling of the sSCell        and configured to monitor on the primary cell for scheduling of        primary cell is no more than 3+3=6.

Additionally, there may be a per-scheduled cell or a per-scheduled andscheduling cell limitations, e.g., wireless device 22 is not expected tohandle a configuration that results in one or more of:

-   -   the total number of different DCI sizes configured to monitor        for the primary cell for scheduling of the primary cell is no        more than 4;    -   the total number of different DCI sizes with C-RNTI configured        to monitor on the primary cell for scheduling of the primary        cell is no more than 3.

“Non-Uplink CA Case or when sSCell is DL-Only”

Wireless device 22 is configured with a primary cell, and the wirelessdevice 22 is configured with an SCell that has no uplink (e.g., noPUSCH-Config, etc.). The SCell is also configured as an sSCell. Sincethere is no uplink for the sSCell, the corresponding UL DCI formats areunused. Wireless device 22 such as via one or more of processingcircuitry 84, processor 86, radio interface 82, operation unit 34, etc.,can be configured to monitor uplink DCI formats (e.g. 0-0 and/or 0-1and/or 0-2) for scheduling primary cell on the sSCell.

In one or more embodiments, there is no carrier indicator field neededin the DCI formats on the sSCell scheduling the primary cell. In one ormore embodiments, there is no carrier indicator field needed in the DCIformats monitored on the primary cell.

The uplink DCI format monitored on the sSCell may schedule the primarycell only. On the sSCell, a same search space can be reused to scheduledownlink DCI format scheduling sSCell and uplink DCI format schedulingprimary cell.

On the sSCell, a single DCI size budget and DCI size matching can beapplied to the DCI format(s) scheduling sSCell (e.g., downlink DCIformat scheduling sSCell) and DCI format(s) scheduling primary cell(e.g., uplink DCI format scheduling primary cell).

An example is illustrated in FIG. 14 where the blocks with hatchingsillustrate the DCIs intended for the primary cell scheduling. The DCIformat 0-1 on the sSCell may be used for scheduling the primary cell.

Default QCL Assumption for Enhanced CCS

In cases of enhanced CCS from sSCell to primary cell, when the PDCCH toPDSCH gap is less than a certain/predefined threshold, the default TCIstate for that PDSCH can be given by one of the following:

-   -   the TCI state of the SS set on the primary cell is linked to the        SS on which the PDCCH is detected on the sSCell.    -   the TCI state of a reference SS set/CORESET on the primary        cell—the reference SS set can be the SS set with lowest or        highest search space ID that is monitored in the slot        overlapping the slot in which the PDCCH scheduling the PDSCH is        received on the sSCell.

Therefore, one or more embodiments described herein advantageously allowan SCell (referred to as a special SCell or sSCell) to schedulePDSCH/PUSCH on a primary cell.

DCI handling for the primary cell scheduling when sSCell is configured,including one or more following aspects:

Example embodiments of moving a single DCI format to sSCell, asdescribed herein such as in the “Moving only one DCI format to sSCell”section.

Example embodiments are described in the “Use same size for a DCI formatfor the primary cell when the DCI format is monitored on both cells”section where the same size for a DCI format for the primary cell isused when DCI format is monitored on both cells. Introducing CIF on bothprimary cell and sSCell for a given DCI format scheduling primary cellis also provided.

Example embodiments where sScell scheduling primary cell is treated asextra virtual carrier for which DCI budgets are applied separately areprovided as described herein such as in the “Separate DCI size budgettreating ‘sSCell scheduling of primary cell’ as an extra virtual cell”section.

Example embodiments where sScell scheduling primary cell shares thesSCell budget or applying an aggregate budget over primary cell andsSCell are provided as described herein such as in the “Borrowing DCIsize from the sSCell budget or applying an aggregate budget over primarycell and sSCell” section.

Example embodiments for non-uplink CA case or when sSCell is DL-onlyincluding operation without introducing an explicit carrier indicatorfield as provided as described herein such as in the “Non-uplink CA caseor when sSCell is DL-only” section.

As will be appreciated by one of skill in the art, the conceptsdescribed herein may be embodied as a method, data processing system,computer program product and/or computer storage media storing anexecutable computer program. Accordingly, the concepts described hereinmay take the form of an entirely hardware embodiment, an entirelysoftware embodiment or an embodiment combining software and hardwareaspects all generally referred to herein as a “circuit” or “module.” Anyprocess, step, action and/or functionality described herein may beperformed by, and/or associated to, a corresponding module, which may beimplemented in software and/or firmware and/or hardware. Furthermore,the disclosure may take the form of a computer program product on atangible computer usable storage medium having computer program codeembodied in the medium that can be executed by a computer. Any suitabletangible computer readable medium may be utilized including hard disks,CD-ROMs, electronic storage devices, optical storage devices, ormagnetic storage devices.

Some embodiments are described herein with reference to flowchartillustrations and/or block diagrams of methods, systems and computerprogram products. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer (to therebycreate a special purpose computer), special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

These computer program instructions may also be stored in a computerreadable memory or storage medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer readablememory produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide steps for implementing the functions/acts specified inthe flowchart and/or block diagram block or blocks.

It is to be understood that the functions/acts noted in the blocks mayoccur out of the order noted in the operational illustrations. Forexample, two blocks shown in succession may in fact be executedsubstantially concurrently or the blocks may sometimes be executed inthe reverse order, depending upon the functionality/acts involved.Although some of the diagrams include arrows on communication paths toshow a primary direction of communication, it is to be understood thatcommunication may occur in the opposite direction to the depictedarrows.

Computer program code for carrying out operations of the conceptsdescribed herein may be written in an object oriented programminglanguage such as Java® or C++. However, the computer program code forcarrying out operations of the disclosure may also be written inconventional procedural programming languages, such as the “C”programming language. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer. In the latter scenario, theremote computer may be connected to the user's computer through a localarea network (LAN) or a wide area network (WAN), or the connection maybe made to an external computer (for example, through the Internet usingan Internet Service Provider).

Many different embodiments have been disclosed herein, in connectionwith the above description and the drawings. It will be understood thatit would be unduly repetitious and obfuscating to literally describe andillustrate every combination and subcombination of these embodiments.Accordingly, all embodiments can be combined in any way and/orcombination, and the present specification, including the drawings,shall be construed to constitute a complete written description of allcombinations and subcombinations of the embodiments described herein,and of the manner and process of making and using them, and shallsupport claims to any such combination or subcombination.

Abbreviations that may be used in the preceding description include:

Abbreviation Explanation ACK Acknowledgment ACK/NACKAcknowledgment/Not-acknowledgment BD Blind Decode BWP Bandwidth Part CBGCode Block Group CCE Control Channel Element DAI Downlink AssignmentIndicator DCI Downlink Control Information HARQ Hybrid Automatic RepeatRequest MIMO Multiple Input Multiple Output NACK Not-acknowledgmentPDCCH Physical Downlink Control Channel PDSCH Physical Shared DataChannel PMO PDCCH Monitoring Occasion PUCCH Physical Uplink ControlChannel TB Transport Block UCI Uplink Control Information

It will be appreciated by persons skilled in the art that theembodiments described herein are not limited to what has beenparticularly shown and described herein above. In addition, unlessmention was made above to the contrary, it should be noted that all ofthe accompanying drawings are not to scale. A variety of modificationsand variations are possible in light of the above teachings.

EMBODIMENTS

Embodiment A1. A network node operating as a secondary cell andconfigured to communicate with a wireless device (WD) and a primary cellfor the wireless device, the network node configured to, and/orcomprising a radio interface and/or comprising processing circuitryconfigured to:

-   -   schedule at least one of a physical shared channel and physical        control channel on the primary cell for the wireless device; and    -   optionally cause transmission of the scheduling.

Embodiment A2. The network node of Embodiment A1, wherein the schedulingof at least one of the physical shared channel and physical controlchannel on the primary cell is performed by a physical downlink controlchannel, PDCCH, on the secondary cell.

Embodiment A3. The network node of Embodiment A1, wherein a downlinkcontrol information, DCI, budget for the wireless device for both theprimary cell and secondary cell corresponds to a total number of DCIssizes that the wireless device is provided is shared among the primarycell and is the same as the DCI budget for one of the primary cell andsecondary cell.

Embodiment B1. A method implemented in a network node that is operatingas a secondary cell and that is configured to communicate with awireless device (WD) and a primary cell for the wireless device, themethod comprising:

-   -   scheduling at least one of a physical shared channel and        physical control channel on the primary cell for the wireless        device; and    -   optionally causing transmission of the scheduling.

Embodiment B2. The method of Embodiment B1, wherein the scheduling of atleast one of the physical shared channel and physical control channel onthe primary cell is performed by a physical downlink control channel,PDCCH, on the secondary cell.

Embodiment B3. The method of Embodiment B1, wherein a downlink controlinformation, DCI, budget for the wireless device for both the primarycell and secondary cell corresponds to a total number of DCIs sizes thatthe wireless device is provided is shared among the primary cell and isthe same as the DCI budget for one of the primary cell and secondarycell.

Embodiment C1. A wireless device configured to communicate with aprimary cell and a secondary cell, the wireless device configured to,and/or comprising a radio interface and/or comprising processingcircuitry configured to:

-   -   receive scheduling from the secondary cell, the scheduling        configured to schedule at least one of a physical shared channel        and physical control channel on the primary cell for the        wireless device; and    -   optionally operate according to the received scheduling.

Embodiment C2. The wireless device of Embodiment C1, wherein thescheduling of at least one of the physical shared channel and physicalcontrol channel on the primary cell is received via a physical downlinkcontrol channel, PDCCH, on the secondary cell.

Embodiment C3. The wireless device of Embodiment C1, wherein a downlinkcontrol information, DCI, budget for the wireless device for both theprimary cell and secondary cell corresponds to a total number of DCIssizes that the wireless device is provided is shared among the primarycell and is the same as the DCI budget for one of the primary cell andsecondary cell.

Embodiment D1. A method implemented by a wireless device that isconfigured to communicate with a primary cell and a secondary cell, themethod comprising:

-   -   receiving scheduling from the secondary cell, the scheduling        configured to schedule at least one of a physical shared channel        and physical control channel on the primary cell for the        wireless device; and    -   optionally operating according to the received scheduling.

Embodiment D2. The method of Embodiment D1, wherein the scheduling of atleast one of the physical shared channel and physical control channel onthe primary cell is received via a physical downlink control channel,PDCCH, on the secondary cell.

Embodiment D3. The method of Embodiment D1, wherein a downlink controlinformation, DCI, budget for the wireless device for both the primarycell and secondary cell corresponds to a total number of DCIs sizes thatthe wireless device is provided is shared among the primary cell and isthe same as the DCI budget for one of the primary cell and secondarycell.

1. A network node operating a secondary cell and configured tocommunicate with a wireless device (WD) and a primary cell for thewireless device, the network node comprising a radio interface andprocessing circuitry configured to: schedule a physical shared channelon the primary cell for the wireless device using a physical downlinkcontrol channel, PDCCH, on the primary cell and a physical downlinkcontrol channel, PDCCH, on the secondary cell, the size of DCI formatused for the primary cell being size-matched to the size of the DCIformat used for secondary for the secondary cell. 2.-4. (canceled) 5.The network node of claim 1, wherein both the DCI format used for theprimary cell and the DCI format used for the secondary cell include acarrier indicator field.
 6. The network node of claim 1, wherein thesecondary cell is a special secondary cell.
 7. A method implemented in anetwork node that is operating as a secondary cell and that isconfigured to communicate with a wireless device (WD) and a primary cellfor the wireless device, the method comprising: scheduling a physicalshared channel the primary cell for the wireless device using a physicaldownlink control channel, PDCCH, on the primary cell and a physicaldownlink control channel, PDCCH, on the secondary cell, the size of DCIformat used for the primary cell being size-matched to the size of theDCI format used for secondary for the secondary cell. 8.-10. (canceled)11. The method of claim 7, wherein both the DCI format used for theprimary cell and the DCI format used for the secondary cell include acarrier indicator field.
 12. The method of claim 7, wherein thesecondary cell is a special secondary cell.
 13. A wireless deviceconfigured to communicate with a primary cell and a secondary cell, thewireless device comprising a radio interface and processing circuitryconfigured to: receive scheduling from the primary cell using a physicaldownlink control channel, PDCCH, and scheduling from the secondary cellusing a physical downlink control channel, PDCCH, the schedulingconfigured to schedule a physical shared channel on the primary cell forthe wireless device, the size of DCI format used for the primary cellbeing size-matched to the size of the DCI format used for secondary forthe secondary cell. 14.-16. (canceled)
 17. The wireless device of claim13, wherein both the DCI format used for the primary cell and the DCIformat used for the secondary cell include a carrier indicator field.18. The wireless device of claim 13, wherein the secondary cell is aspecial secondary cell.
 19. A method implemented by a wireless deviceconfigured to communicate with a primary cell and a secondary cell, themethod comprising: receiving scheduling from the primary cell using aphysical downlink control channel, PDCCH, and scheduling from thesecondary cell using a physical downlink control channel, PDCCH, thescheduling configured to schedule a physical shared channel on theprimary cell for the wireless device, the size of DCI format used forthe primary cell being size-matched to the size of the DCI format usedfor secondary for the secondary cell. 20.-22. (canceled)
 23. The methodof claim 19, wherein both the DCI format used for the primary cell andthe DCI format used for the secondary cell include a carrier indicatorfield.
 24. The method of claim 19, wherein the secondary cell is aspecial secondary cell.